Human Anatomy Parts 3-4 Flashcards
Adrenal cortex
outer portion of the adrenal gland
Adrenal glands
a pair of endocrine glands just above the kidneys
Adrenal medulla
the inner portion of the adrenal glands that secretes epinephrine and norepinephrine which produces our fight-or flight responses
Amygdala
processes emotional memories and generates emotions
Autonomic nervous system
Controls involuntary muscles and glands
Axon
long extension from the soma carries messages away from the soma
Axon terminals
finger-like projections at the end of the axon
Blood brain barrier
composed of tightly packed cells that prevent large, unwanted molecules from entering the brain
Brain stem
connects to the spinal cord, and controls involuntary functions
Central nervous system
brain and spinal cord enclosed and protected by the skull and vertebrae
Cerebellum
a) Found at the back of your head under the cerebrum; divided into left and right hemispheres
b) Functions to coordinate skeletal muscle activity
Cerebral cortex
outer layer of the cerebrum
Cerebrum
upper portion of the brain, divided into left and right hemispheres
Chemoreceptors
respond to chemicals; in your nose
Circadian rhythm
the biological clock; regular bodily rhythms that occur on a 24-hour cycle
Cochlea
a coiled, bony, fluid-filled tube in the inner ear; vibrations are sent through and stimulate sensory hair cells and are converted to nerve impulses
Cones
detect color
Cornea
the transparent outer covering of the eye
Corpus callosum
mass of nerve fibers allowing the hemispheres to communicate
Dendrites
finger-like projections carry messages toward the soma
Endocrine system
a) Includes: pituitary gland, thyroid gland, pineal gland, and the adrenal gland
b) Function: sends chemical messages through the body
Frontal lobes
found under the forehead; the center of reasoning, planning, movement, emotions, problem solving, and some parts of speech
Gland
An organ that produces and releases chemicals either through ducts or into the bloodstream
Glial cells
support, nourish, and protect neurons
Gonads
glands that produce sex hormones
Gray matter
composed primarily of nerve cell bodies; responsible for processing information
Hippocampus
processes factual memories
Hormones
chemical messengers
Hypothalamus
area of the brain that secretes hormones that regulate the pituitary gland
Incus
anvil; middle of the three auditory ossicles of the middle ear
Islet of Langerhans
a group of cells in the pancreas which release the hormone insulin and others release the hormone glucagon which work to balance blood glucose levels
Lens
Focuses light onto retina
Limbic system
groups of nerves around the brainstem
Interneurons
interpret the sensory signal and transfer the message from the brain and spinal cord to muscles and glands
Malleus
hammer; first of the three auditory ossicles of the middle ear
Mechanoreceptors
respond to touch, pressure, vibration, stretch, and itch
Motor neurons
convert the message received from the brain and spinal cord to stimulate muscles and glands
Neuron
electrically excitable cells that carry messages throughout the body
Neurotransmitters
molecules released at the axon terminal which travel across the synaptic cleft where they stimulate receptor proteins in the next neuron
Occipital lobes
found in the back of the head; receives input from your eyes and referred to as the visual cortex
Ovaries
female reproductive glands that produce estrogen
Pain receptors
react by causing you to feel pain
Pancreas
part of the endocrine system;
1. Releases digestive enzymes to help break down food 2. Contains a group of cells, the Islet of Langerhans, some of which release the hormone insulin and others release the hormone glucagon which work to balance blood glucose levels
Papillae
taste buds; tiny bumps on the surface of the tongue
Parasympathetic nervous system
your rest-repose response; sends signals to decrease your heart rate and blood pressure, and contracts stomach muscles for digestion
Parathyroid glands
- Four parathyroid glands, two embedded on each side of the thyroid gland
- Secrete parathyroid hormone which works opposite of calcitonin to increase blood calcium levels
Parietal lobes
portion of the cerebral cortex lying at the top of the head and toward the rear; receives sensory input for touch and body position
Peripheral nervous system
nerves running through the body that arise from the brain and spinal cord
Photoreceptors
cause nerve impulses to be carried by the optic nerve to the brain
Pineal gland
- Located deep in the brain
- Primarily responsible for regulating your body’s wake and sleep cycle
- When light is detected, it secretes serotonin
- When no light is detected, it secretes melatonin
Pituitary gland
the master gland of the endocrine system
Pupil
opening in the center of the iris
Reflex arc
the nerve pathway involved in a reflex action
Retina
Light sensitive layer of the eye; contains rods and cones
Rods
Retinal receptors that detect black, white, and gray
Saccule
part of the inner ear; detects backward-forward motion and upward-downward motion
Semicircular canals
serve as balance sensors and detect left and right tilting, side-to-side motion, and up and down motion
Sensory neurons
detect sensory stimuli and carry impulses to the spinal cord and brain
Sensory organs
receive impulses from environment and relay impulses to brain including skin, tongue, nose, eyes, and ears
Soma
cell body of a neuron
Stapes
stirrup; last of the three auditory ossicles of the middle ear
Sympathetic nervous system
your fight-or-flight response; sends signals to raise your heart rate and blood pressure and stimulates your liver to release glucose to produce quick energy
Synaptic clef
space between two neurons
Target cells
cells with receptors that respond to specific hormones
Temporal lobes
found on the sides of the head; associated with speech perception, hearing, and some types of memory
Testes
male reproductive glands that produce androgens, including testosterone
Thalamus
routes signals to various parts of the body
Thermoreceptors
respond to temperature changes
Thymus
- Where T-cells are made, mature, and are trained for what to fight and what to leave alone
- T-cells that attack invaders enter the bloodstream and reside in the lymphatic tissue
Thyroid gland
- Thyroxine: regulates metabolic rate
- Calcitonin: causes excess blood calcium to be stored in the bones
Tympanic membrane
eardrum
Utricle
part of the inner ear; detects backward-forward motion and upward-downward motion
White matter
composed primarily of myelinated axons; responsible for carrying information
Adenoids
an area of the body where lymph nodes are clustered together creating a protective ring against invaders that may enter through the mouth or nose
Arrector pili
smooth muscles attached to hair follicles
Basophils
produced in the bone marrow and are responsible for allergic reactions
Chyle
the term used when lymph fluid collects fat it turns a milky color
Collagen
protein that give skin the ability to stretch and return to its original shape
Dermis
second layer of skin tissue
Elastin
protein that give skin the ability to stretch and return to its original shape
Eosinophils
produced in the bone marrow and release a chemical that attacks large multicellular parasites
Epidermis
top layer of skin tissue
Epithelial cells
skin cells; rapidly reproduce to replace cells that are lost by pushing cells to the surface
Germinative
Living cells that reproduce rapidly
Hair follicle
tiny pockets in the dermis from which hair grows
Integumentary system
a) Includes: skin, hair, and nails
b) Function: protection and sensory input
Keratin
hard protein material found in the epidermis, hair, and nails
Lingual tonsils
an area of the body where lymph nodes are clustered together creating a protective ring against invaders that may enter through the mouth or nose
Lymph nodes
act as filtering and monitoring stations that clean the lymph of dead cells and foreign invaders
Lymph vessels
move the fluid to the lymph nodes
Lymphocytes
- T-cells: made and mature in the thymus gland; attack invaders directly
- B-cells: made in the bone marrow and mature in the spleen; make antibodies to fight specific invaders
- Natural killer cells: recognize tumor cells and cells that have been infected with viruses and kill the infected cells
Melanin
skin pigment
Melanocytes
produce melanin
Monocytes
produced in the bone marrow, are the largest white blood cells in the human body
Neutrophils
produced in the bone marrow and respond quickly to hold off pathogens
Palatine tonsils
areas of the body where lymph nodes are clustered together creating a protective ring against invaders that may enter through the mouth or nose
Sebaceous glands
secrete an oil called sebum which softens and waterproofs your skin
Sebum
an oil secreted by the sebaceous glands which softens and waterproofs your skin
Spleen
the largest lymphatic organ
Squamous
flattened dead cells resembling scales
Sweat glands
help regulate body temperature and rid the body of waste products
Thymus gland
- Where T-cells are made, mature, and are trained for what to fight and what to leave alone
- T-cells that attack invaders enter the bloodstream and reside in the lymphatic tissue
Vestigial
organs that do not appear to have a function or purpose
